Converting between Interlaced and Progressive

[interpost]

Hello,

I have a question regarding conversion between 1080i/60i and 720p/60p. We would like to shoot footage and offer it as stock footage. Is there a tried and true way of shooting and then later converting between the two formats that works best so that we can offer the highest quality footage in both formats?
I've shot some footage both ways and tried simply exporting using QT conversion from FCP. My conclusion is that 720p to 1080i (both at 60) introduces some choppiness, while going from 1080i to 720p looks pretty good. Granted QT conversion is probably not the best way to do this. If there is a good way of doing this please let me know, the HPX book seemed to dodge the question on page 79 so I'm afraid it becomes an either/or situation where neither one really looks better than the other. Thanks for any insight anyone can provide.

[David Saraceno]

You need to set of a custom preset in Compressor that uses the frame controls to convert to progressive.

Exporting using QT conversion will not work well.

[interpost]

So it's a better move to shoot 1080i and convert to 720p rather than vice versa? I've done some tests in compressor and converting both ways seems good to me, but I'm not set up for HD playback on an external monitor, so I've only got movie files on the computer to look at. I would think that if there's any issue with converting to interlaced or back, I wouldn't be able to see it on my computer screen, which is what has me worried.